Comprehensive & Systematic Reviews

Before starting your systematic review, it's a wise idea to search for systematic reviews that are related to your research question. Here's a tutorial on how to find systematic reviews in PubMed. There are several reasons to do this:

• Ensure that you're not needlessly duplicating past work.
• Help you describe how your systematic review will uniquely contribute to the field (if there are existing systematic reviews) or how it will fill a gap (if there are not existing systematic reviews). 
• Give you ideas of how to structure your search strategy or final report. 

Treadwell librarians can search for systematic reviews that may be related to your topic. Just Ask Us!

There are four steps to creating systematic review search strategies:

• Determining the main concepts of your research question that you would like to include in your search.
• Brainstorming keywords related to your main concepts. 
• Determining subject headings related to your main concepts in each of the databases your plan to search. The subject headings (or MeSH terms) for a topic in MEDLINE may be different from the subject headings for the same concept in Embase, for instance.
• Designing and executing the search strategy in your databases of choice. This involves searching for keywords in the titles/abstracts of citations and combining them with the subject headings that you chose. Each database has its own set of commands to use that will necessitate modifying your search strategy.

The search strategy should be proofread or peer reviewed carefully. We recommend using the 2015 PRESS guidelines to evaluate your search.

If this sounds complicated, never fear! Treadwell librarians can help you with this process and even design systematic search strategies for you. Ask Us to get started. 

Core databases to include in systematic review searches include the following:

• Ovid (MEDLINE) or PubMed
• Embase 
• Web of Science
• clinicaltrials.gov to identify unpublished studies

Subject specific databases may be indicated, depending on the research topic. Examples include:

• CINAHL
• PsycInfo

Finally, once you identify the set of articles you want to include in your systematic review, you can use a database like Web of Science to identify studies that have cited your articles of interest. 

Treadwell librarians can help you:

• Choose databases for your search
• Create and execute searches in any or all of the above databases. 

All of these databases, with the exceptions of Embase and Web of Science, can be access via the Resources box on the Treadwell homepage. Embase and Web of Science are available via Harvard. If you are not eligible for Harvard access, a Treadwell librarian can search these resources for you.

Learn more about:

• Obtaining access to Harvard and eCommons
• Searching for grey literature (guide from Duke University Medical Center Library)

We recommend avoiding using filters or limits in databases to restrict your systematic review search to certain study methodologies.

Countway Library describes the issues with incorporating methodology filters into your search and provides a list of appropriate filters to use on their page, "Why use a filter for the study methodology? Why not?"

If you do choose to use a search filter in your search, the ISSG Search Filters Resource is another good source of validated filters.